• Journal of Adhesion and Interface
• /
• v.16 no.4
• /
• pp.146-151
• /
• 2015

Raw sap of essential oil in Korean Dendropanax lacquer was extracted with ethanol, and which was cured by using ROMP (ring opening metathesis polymerization, one of olefin metathesis). Curing behavior with subsequent film properties were studied and compared with conventional curing (under ambient conditions) and UV photo curing. The compositional changes of major ingredients in the lacquer before and after curing were studied by using GC-MS (gas chromatography mass spectrometry). ROMP-cured coating film showed higher gel contents (40%) as compared to those of conventional (8%) and UV curing (25%). ROMP curing with 2 wt% Grubbs' catalyst at $100^{\circ}C$ completed curing reaction within 2 h, which was much faster than that of conventional curing. The quality of coating film prepared with ROMP was more homogeneous and wrinkle-free as compared with that with UV curing. It was found that major ingredients of sesquiterpenes, such as ${\alpha}$-selinene, ${\beta}$-selinene, and ${\delta}$-cadinene were reacted in ROMP, as well as polyacetylenes.

• Journal of Digital Contents Society
• /
• v.18 no.2
• /
• pp.347-356
• /
• 2017

It is well-known that the face recognition method via sparse representation has been proved very robust and showed good performance. Its weakness is, however, that its time complexity is very high because it should solve $L_1$-minimization problem to find the sparse solution. In this paper, we propose to use the ROMP(Regularized Orthogonal Matching Pursuit) method for the sparse solution, which solves the $L_2$-minimization problem with regularization condition using the greed strategy. In experiments, we shows that the proposed method is comparable to the existing best $L_1$-minimization solver, Homotopy, but is 60 times faster than Homotopy. Also, we proposed C-SCI method for classification. The C-SCI method is very effective since it considers the sparse solution only without reconstructing the test data. It is shown that the C-SCI method is comparable to, but is 5 times faster than the existing best classification method.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.1037-1040
• /
• 2006

This paper presents an efficient overlay multicast routing protocol (ROMP) and its architecture. ROMP using GPS and region map stands on the basis of scalable 2-tiered multicast architecture and maintains a global overlay multicast tree through reactive fashion. With this approach, the coarse-grain location-awareness for an efficient overlay multicasting and the determination of hot-spot area for efficient data delivery are feasible. The simulation results show that the localized control packets of ROMP prevent the overlay control packets from squandering the physical network resources.

• Polymer(Korea)
• /
• v.39 no.3
• /
• pp.506-513
• /
• 2015

Ethylidene norbornene (ENB) and its blends with endo-dicyclopentadiene (endo-DCPD) were prepared and reacted via the ring-opening metathesis polymerization (ROMP) reaction with the $1^{st}$ and $2^{nd}$ generation Grubbs' catalysts. Dynamic exothermic behaviors during ROMP and tensile properties after ROMP were evaluated using a differential scanning calorimeter (DSC) and a universal testing machine (UTM) for the samples, respectively. It revealed that the ROMP rate was accelerated with the less contents of endo-DCPD and under the $2^{nd}$ generation catalyst. Also, the addition of endo-DCPD and the $1^{st}$ generation catalyst resulted in higher tensile modulus and strength but lower toughness. Gel fraction measurement and fracture surface observation were made to understand the tensile properties.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.spc8
• /
• pp.3074-3080
• /
• 2011

We synthesized three novel poly(norbornene bisimide)s by ring opening metathesis polymerization (ROMP) and subsequent hydrogenation. Their thermal, mechanical and optical properties were investigated with TGA, DMA, UV-Vis spectrometer, and optical reflectometer. The new polymers showed high glass transition temperatures over $260^{\circ}C$ and good thermal stability with 5% wt-loss temperature higher than $390^{\circ}C$. When solvent casted, they yielded optically transparent and dimensionally stable films with a relatively low coefficient of thermal expansion of about 50 ppm $K^{-1}$. Therefore, the bisimide moieties substantially enhanced thermal and dimensional stabilities, as compared with normal ROMP-prepared polynorbornene films. Though the water uptake was increased to 0.6 wt-%, this water uptake is still considerably lower than that for polyethersulfones (1.4 wt-%) or polyimides (2.0 wt-%). Hence, the new poly(norbornene bisimide)s may become attractive candidates for flexible substrates of optoelectronic devices such as displays and photovoltaic solar cells.

• Polymer(Korea)
• /
• v.30 no.4
• /
• pp.311-317
• /
• 2006

Poly-DCPD and poly-DCPD/silicates hybrids were prepared by in-situ ROMP poly-merization using $WCl_6$ catalyst. Good dispersion of silicates in DCPD medium can be accomplished by sonication method. Compared with nanocomposites prepared using $Na^+MMT$, the nanocomposites with CL 15A showed well dispersed silicate's morphology. superior thermal and mechanical properties. Additionally, well dispersed silicates in DCPD matrix enhanced the gas barrier property of the nanocomposites.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.1668-1673
• /
• 2008

고분자 복합재 구조물의 경우 일반적으로 여러 층의 단층(laminar)이 적층된 구조로 이루어져 있으며, 모재균열, 층간분리 및 섬유파단과 같은 손상이 발생되어 파단에 이르게 된다. 자가손상 복구기법은 복합소재의 열경화성 수지 내에 손상복구액을 포함하고 있는 마이크로캡슐과 촉매를 투입하여 외부의 도움 없이 손상을 치료할 수 있는 방법으로, 소재의 디자인에 있어서 새로운 페러다임을 제공할 수 있는 것으로 현재 많은 연구가 진행되고 있다. 본 연구에서는 ENB(5-ethylidene-2-norbornene)와 DCPD(dicyclopentadiene)에 대하여 DMA(dynamic mechanical analysis)와 DSC(differential scanning calorimetry)를 이용하여 특성을 분석하였다. 또한 그들의 ROMP(ring-opening metathesis polymerization)반응과의 관계를 조사하였으며, ENB와 DCPD 블렌드에 대한 복구액으로서의 특성도 조사하였다. 본 연구실에서 합성된 두 가지 다른 종류의 ROMP 경화제에 대한 실제 자가손상복구에으로서의 적용상 특성도 연구하였다.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.8
• /
• pp.2737-2742
• /
• 2011

Ring-opening metathesis polymerization (ROMP) of an ethyl-substituted tetracyclododecene (8-ethyltetracyclo[$4.4.0.1^{2,5}.1^{7,10}$] dodec-3-ene, Et-TCD) was carried out in the presence of a ternary catalyst system consisting of $WCl_6$, triisobutyl aluminium (iso$Bu_3Al$), and ethanol. The optimal molar ratio of Et-TCD/$WCl_3$/iso-$Bu_3Al$/ethanol was found as 500/1/3/2 at which the yield of ring-opened polymer was 100%. 1-Hexene was shown to be an effective molecular weight controlling agent for ROMP reaction of Et-TCD. The hydrogenation of the ring opened polymer (p-Et-TCD) was conducted successfully using Pd(5 wt %)/${\gamma}$-$Al_2O_3$ at $80^{\circ}C$ for 1 h. Chemical structures of p-Et-TCD and its hydrogenated product($H_2$-p-Et-TCD) were characterized using 2D NMR techniques ($^1H-^1H$ COSY and $^1H-^{13}C$ HSQC). The changes of physical properties such as thermal stability, glass transition temperature and light transmittance after the hydrogenation were also investigated using TGA, DSC, and UV.

• Journal of Power System Engineering
• /
• v.19 no.5
• /
• pp.86-92
• /
• 2015

p-DCPD were prepared by in-suit ROMP polymerization using $MoCl_5$ and $Et_2AlCl$. The results showed that $MoCl_5:Et_2AlCl:DCPD$ mole ratio of 1:2.0:350 had the curing-time of 60sec and crosslinking degree of 90.44%. The curing time of DCPD polymerization by $MoCl_5/Et_2AlCl$ was shortened, and monomer conversion and crosslinking degree were decreased with temperature and the number of moles of $MoCl_5$ and $Et_2AlCl$. $MoCl_5$ and $Et_2AlCl$ is damaged its function by the reaction with the air in the atmosphere and did't proceed the polymerization properly.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.200-200
• /
• 2006

Several polynorbornene or poly(norbornene-7-oxide) based functional block copolymers were synthesized by ring opening metathesis polymerization (ROMP) with good molecular weight and polydispersity control. Some representative functional groups in these polymers are a nitrobenzoyl group or ferrocene. These polymers were subjected to various chemical modification reactions to give other block copolymers that contain novel functionality such as amine, diazonium salt, and diazo groups. The resulting polymers were characterized by various techniques such as GPC, NMR, UV-VIS, AFM, and cyclovotammography (CV).